1. Technical Field
This invention relates to a testing apparatus for off-load and on-load unhooking simulation of the release device of a closed lifeboat, particularly to one installation for carrying out unhooking simulation in a lifeboat drill as so to enhance the safety of operators.
2. Description of the Prior Art
In view of the sinking accident of the Titanic passenger liner in 1912, which caused serious casualties, the International Maritime Organization (IMO) has paid much attention to the completion and maintenance of a ship's lifesaving equipment, and the International Convention for the Safety of Life at Sea (SOLAS) and the International Life-Saving Appliance Code (LSA) have prescribed that all the international voyage ships must be equipped with lifeboats and large merchant ships, passenger liners and ferry boats must periodically carry out operation drill of lifeboats and further prescribed that under what condition, it is necessary to carry out lifesaving drill when the ship's personnel is changed. The lifesaving system of a ship is the last line of defense of life safety at sea, having important function of rescuing a ship's personnel in case of emergency, and lifeboats are statutory lifesaving equipment of a ship and safety of the ship's lifeboats is worthy of attention whether during shipwreck or during lifesaving drill in normal times. Accidents happened endlessly all over the world during lifeboat drills, and the most of the accidents frequently happened during the lifeboat's launching which always caused serious casualties.
The Maritime Safety Committee of the International Maritime Organization prescribed on the paragraph “MSC 82/24 4.4.18.2.2” that a lifeboat must be able to off-load and on-load release hooks, and on-load release hooks must be able to bear 1.1 times of gross weight. On the paragraph “MSC 82/24 4.4.18.8” further prescribed that the strength of a lifeboat's on-load unhook must be able to bear 6 times of gross weight, and the suspending equipment used for maintenance and service of the unhook must have capacity of carrying the gross weight plus 1000 kgs. Conventional suspending equipment 1 employed for simulating hooks release of a lifeboat, as shown on FIG. 1, is generally provided with two chain brakes 10 respectively disposed with a chain 11 having one end fixed with a suspending hook 12. The two chain brakes 10 are respectively hung on two davit arms 13, and the two suspending hooks 12 are respectively hooked on the bow and the stern of a lifeboat 14. To carry out drill of simulating launching and hook release of the lifeboat 14, two people respectively on the bow and the stern of the lifeboat 14 must be ready to apply force at the same time to pull the chains 11 on the two chain brakes 10 for slightly lifting the lifeboat 14, letting the lifeboat 14 simulate shifting upward after launching, and at this time, the hook releasing of the lifeboat 14 can be performed, thus completing the drill which is the unhooking simulation of the lifeboat 14 after launching the lifeboat 14. However, it requires two peoples to operate the conventional suspending equipment at the same time for lifting the lifeboat 14; nevertheless, during pull of the chains 11, the strength applied by each person is not the same; therefore, the lifeboat 14 cannot be lifted in a horizontal and may produce a slanting state and result in failure in the releasing hooks. Further, the conventional suspending equipment has no indication function of lifting height and load and hence the two operators on the bow and the stern of the lifeboat 14 are unable to know the lifting state of the lifeboat; therefore, the lifeboat 14 may be lifted excessively and improperly to hit the davit arms or touch obstructers but still continue to be lifted, or the lifeboat may be pulled forcefully and improperly to cause damage. Furthermore, the conventional hook release drill can be only applicable to an off-load lifeboat. If a lifeboat is on-load, the strength of conventional suspending equipment cannot bear the pulling force produced by fall of gravity of the on-load lifeboat and is apt to be damaged by the fall of gravity and also likely to injure the lifeboat and the operators.
The illegal facts and the misgivings of safety of the conventional suspending equipment of a lifeboat are described as follows:
1. The carrying capacity of the suspending equipment is evidently deficient and safety coefficient is too low.
2. In a whole course, the suspending equipment needs to be operated in the high altitude with high risk.
3. The conventional suspending equipment is operated manually and independently at one side so the lifeboat cannot be suspended safely in horizontal mode, always making the bow and the stern of a lifeboat in different lifting height.
4. In operation, the conventional suspending equipment has no indicating function of lifting height and lifting load; therefore a lifeboat is frequently lifted excessively or forcefully and improperly pulled to cause damage.
5. The conventional suspending equipment is extremely heavy so it is hard to be fastened with the davit arm and the lifeboat and, being not exclusive tools, the conventional suspending equipment causes worry in safety.
A lifeboat must surely be examined whether or not the equipment can be operated normally before launching drill; otherwise failures of unhooking or early release hooks may occur during launching drill. Therefore, how to ensure operators' safety during drills of the lifeboat and provide a safe environment or condition for launching drill is very important.